The M48 Severn Bridge will be closed on Sunday morning for a running event.
The annual Severn Bridge half-marathon will not go ahead this year due to coronavirus but the road between Chepstow in Monmouthshire and Aust in South Gloucestershire will shut for a 10km time trial from 07:30 BST to midday.
A limited entry of 1,250 runners will start at 10-second intervals.
Highways England said a “clearly signed diversion route” would be in place.
Runners taking part will be able to start within a three-hour window, setting off on the westbound carriageway before turning around near Junction 2 of the M48 and heading back eastbound across the bridge.
Gareth Price, of Highways England, said: “We’d like to remind road users to plan ahead, and as well as the bridge closure, local roads are also expected to be a little busier before and after the race.
“Our advice is to check our traffic and travel information channels, set off early and allow plenty of time.”
Highways England said up-to-date travel information would be available on its Twitter feed.